


Spiritale

by Skelitzel



Category: Spiritale, Undertale (Video Game), Undertale AU - Fandom
Genre: Angst, Noragami - Freeform, Soul Eater - Freeform, Story Teaser, Undertale AU, monster weapon, skel's au, spiritale - Freeform
Language: English
Status: Completed
Published: 2016-07-11
Updated: 2016-07-11
Packaged: 2018-07-23 00:44:31
Rating: Teen And Up Audiences
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 3,522
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/7459980
Author URL: https://archiveofourown.org/users/Skelitzel/pseuds/Skelitzel
Summary: <blockquote class="userstuff">
              <p>Monster weapons work and fight alongside humans, protecting and purifying corrupted spirit together as partners. When a being is under the effects of corrupted spirit, they lose their sense of self as it latches onto and magnifies their fears and insecurities. Corrupted spirit causes one to become aggressive or severely depressed, and influences its host to harm themselves or others. A monster or human cannot purify the corruption infecting their soul alone. Depending on the severity of the corruption, if their soul is weak and they fight it their soul will start to shatter. Over time, jealousy wormed its way into the hearts of man and monster, and they began to covet other pairings. Some saw a certain monster’s weapon form as stronger than another, or a human more adept in fighting and purifying. They began to fight internally, hurting both monsters and humans in the process. After this, the monsters voluntarily banished themselves with a few human companions to the Underground in hopes that if they took away the humans' weapons, there would be peace Aboveground. However, monsters sensed suffering and fear from the humans they used to know, and desperately wanted to return to the surface since the chaos only grew.</p>
            </blockquote>





	Spiritale

**Author's Note:**

> I mostly talk about my Undertale AU's on my Tumblr: http://skelegirl-fanfic.tumblr.com but thought I'd post this here too for you guys to see. This AU was inspired by Soul Eater and Noragami, and all monsters are weapons while human are their companions and wielders. I've also renamed determination to spirit.
> 
> This AU's sans has renamed himself Spirit due to some...regrets. When the monsters wanted to return to the surface, he volunteered to work with Gaster and Alphys in the lab to find a way to cut down the barrier. He had a talent for resonating his soul with spirit, and wanted to help find a way to wield more. His soul was infused with Gaster's magic, and he gained the Gasterscythe as a weapon form. His appearance also changed, (sort of like G) and he still enjoys puns but sometimes forgets to lighten up.
> 
>  

“SANS!! GET BACK HERE SANS!”

He pushed himself to run faster, stumbling through the trees and cursing the snow amplifying the sound of his steps as he crushed ice under foot.

“You traitorous punk! Stop running you coward!” Undyne’s voice sounded closer than he’d like, and he fought the urge to look back.

Clutching at his sternum, tears welling up in his socket at the steady thrumming within, but he willed himself to keep moving. Toriel. He had to find Toriel. She would know what to do right? He clawed at his skull, crouching lower and hiding among the trees to steady his soul.

“sans, are you ok?” A small voice said from behind him, making him jump. A Snowdrake hopped out from behind a bush, fluttering their wings and tilting their head to the side, “Do you need help?”

He backed up a few steps, staring at the Snowdrake with a wide eye socket, “N-no I’m fine. I just need to get to the ruins.”

The Snowdrake glanced back toward the sounds of Papyrus and Undyne’s shouting, “It sounds like your brother and Undyne are looking for you.” They turned back, “You’re not lost or something, are you?” They flapped their wings again, “They sound mad…what happened sans?”

With a nervous laugh he started walking away again. “Nothing happened, they’re uh… We’re just playing a game.”

“A game?”

“Yeah that’s it. A game.” He stood up straighter and held one finger to his teeth, “And I’m it, so please don’t tell them you saw me, ok?”

The Snowdrake chirped happily and flew up to the branch, “Games are so much fun! I promise I won’t tell!”  
“Thanks, lil buddy.” He flashed them a smile and waved, “I gotta go now. If they catch me before I reach the ruins, I lose.” His smile faltered a bit at the thought.

They waved their wing as he turned and started moving again, “Good luck, sans! Next time I want to play too!”

He winced and peered out from the trees, ensuring the path was clear before continuing on and muttering under his breath, “You’ll probably be a part of it pretty soon.” His eye spun and sickness welled in his soul as the blackened magic permeated up over Snowdin, fast approaching his hiding place. He looked back toward the town once more before sprinting out of the trees and running down the path, leaping over the tree branch and holding one hand against his sternum.

“WAIT I THINK I SAW HIM!” Papyrus’ voice shouted from the distance.

“No you didn’t!” He yelled back, pushing himself to run faster. He yelped when a wave of bones sprang up from the ground, and he rolled to the right. He picked himself back up and started moving again, squeezing his eye socket shut and searching for a glitch in space. “Why can’t I use my shortcuts?!” He cursed under his breath and ducked as a volley of spears flew by overhead.

“sans! Come back and fight me!” Undyne yelled, her voice sounding much closer than he would’ve liked.

Tears of relief welled in his eye socket when he saw the door, “Oh thank god.” He felt a new rush of spirit in his soul and sprinted toward it, “Toriel!” He pounded on the door with both hands, “Tori!”

“SANS!”

“You can’t keep running you coward!”

He looked over his shoulder, soul thrumming erratically. He couldn’t see them yet, but he could hear their footsteps crunching in the snow. Pounding faster he shouted, “TORIEL!”

“sans?” A voice from beyond the door asked in question, “What’s wrong?”

“Toriel…” He smiled despite the circumstance, “H-how have you been?”

She laughed softly, “I’m well, how are you? You seem stressed.”

Stressed. He seemed stressed. A laugh escaped him, sounding hollow and exhausted. “Maybe a little. Um, Toriel?” He looked back again, shifting from foot to foot. The bushes started to shake as the corrupted magic reached out through the forest, “Could I come in?”

“It’s been a while since you visited. What’s the occasion?” Her voice sounded pleasant and unaware.

“I’ll tell you in a bit. Could you open the door please?” His soul stuttered when the Snowdrake fluttered out onto the path.

“I’m disappointed in you, sans.” She said with a sigh, sending another shock through his soul.

His eye didn’t leave the Snowdrake, and he slowly turned to face it. She knows. She knows I fucked up. “W-why do you say that, Toriel?” He held up his hand, quietly shooing it away.

“You haven’t said a single joke or pun throughout our conversation.” She laughed, “Has your humor run bone-dry?”

The corner of his mouth twitched in a grin, “Good one. I’m sure I can think of some-“ He shook his head as the Snowdrake spread their wings and black corruption leaked from their beak. They cawed and their body began to glow as they flew up and morphed into their weapon form, launching themselves toward him. He ducked, sinking lower to the ground and looking up at the shuriken embedded in the door. “-later if you just let me in first.” He struggled to keep his voice level, carefully reaching up to the star and pulling it out of the door. “Sorry,” He whispered quietly and tossed it into the forest.

“Oh sans I know you usually have a few good puns up your sleeve.” She giggled again, “Why don’t you knock a few out and then I’ll invite you in for some pie.”

“Um, ok let me think.” His skull pounded and he looked to see two shadowy figures cresting up over the hill at the end of the pathway. “Uh… Knock, knock.”

“Who’s there?”

“We found you, coward.” Undyne’s voice echoed down the path.

“Theodore.” He pressed his spine against the door, spreading out his arms and silently begging it to open.

“Theodore who?” She asked sweetly.

“SANS, DID YOU REALLY THINK YOU COULD RUN?”

His feet skidded in the snow as he tried futilely to back up further still, “Th-theodore was locked so I knocked.”

She laughed quietly, “sans, you’ve used that one before, I know you can do better than that.”

A flock of Snowdrakes fluttered out and perched on the tree branches up above, “Ok, ok.” He clicked his teeth, trying to think quickly, “Knock, knock.”

“Who’s there?”

Papyrus’ eye sockets narrowed when he was spotted, “Ima.”

“Ima who?”

Papyrus raised his hand and his soul felt like it was about to break in two, “Ima gonna die if you don’t open this door right NOW!” He shouted and squeezed his sockets shut, bracing himself for Papyrus’ attack. He yelped in surprise when the door behind him vanished, and he fell backward into the Ruins.

Toriel stood over him with her hands on her hips, “A little overdramatic, but I suppose you did try to come up with a new one.” She looked out into the snow, smiling, “Is that your brother? I’d love to see him. Does he like pie too?”

“No!” He got up quickly and pushed the doors shut, muffling the shouts of Papyrus and Undyne. He smiled sheepishly at Toriel’s confused expression, “I mean, uh, no he’s fine. He’s training right now with Undyne, and shouldn’t be distracted with sweets.”

Toriel frowned, clearly unconvinced, “Well, alright.” She helped him off his knees and studied him for a moment. The light was dim, and for that he was grateful, but she still noticed a few things, “You’re taller.”  
“Yeah…” He rubbed the back of his skull, “Hit a bit of a…growth spurt.”

She hummed softly and started walking to her home, “So I take it things at the lab are going well?”

He winced slightly at the sound of disapproval in her tone and followed, “That’s actually what I came to talk to you about. We did manage to collect a high amount of spirit, and I am able to resonate with more than before.” He couldn’t help a little flicker of excitement shine in his voice, “And I have a weapon form now! I can finally tap into the magic in my soul and transform.”

“That’s wonderful, sans.” She glanced back and smiled, “I hope you put it to good use. Remember, monster weapons are meant to assist others, not harm them.”

“Right.” He spoke a little quieter, walking slower and looking down.

She didn’t seem to notice the change in his mood, and called back. “Hurry up now, sans, or the pie will be cold.”

“Oh, sorry,” He jogged to catch up to her, seeing her back as she passed the tree up to her doorstep, “I didn’t think you’d leaf me behind!”

His soul thrummed a little easier when he heard her laughter, “Well, you do look tired. Why don’t you come inside forest?” She walked inside and her voice grew quieter.

He walked slowly, looking up at the tree and listening to the leaves crunch under his heel. Hesitating at the doorway, he held the door jam with one hand and peeked his skull inside. It was lighter here… He rested his free hand over his right eye socket. She’s going to see. He sighed heavily, knowing there wasn’t much he could do to avoid it. He pulled up his hood and quietly shut the door behind him, walking to the living room and sitting down at the table.

Toriel returned with two slices of pie and looked down at his feet, “Your footsteps sound a lot heavier than before.” She smiled, “So you’re not wearing slippers anymore?”

He blushed and leaned against the table, tapping his boot against the leg of the chair, “No…I kept falling down and slipping whenever I trained, so Muffet made these boots for me.”

“How nice of her. It’s been a while since I’ve seen her.” She set a plate down in front of him, and pulled out another chair for herself. After she settled, she gazed at him curiously, “Are you cold, sans?” She gestured to the fireplace, “You could sit in the arm chair if that’s more comfortable for you.”

“What? No, I’m not cold.” His soul started to ache again and he hid the right side of his skull deeper in his hood, meeting her eyes. “But, uh, thanks.”

She tilted her head to the side, “Your eye’s changed as well.” She sighed, a sad smile on her face as she looked down at her pie, “You’re taking care of yourself, aren’t you?”

“Of course I am.” Well, mostly.

Her frown increased, “I don’t know what you’re doing in the lab, but you know how I feel about the experiments.”

He sighed, “Yeah…I know.” He rested a hand over his sternum again, “Which is why I-“

“I don’t think hurting yourself to try to save us will work, sans.” She met his eye again, “You’re being careful, right? How are the humans? How’s-“ Her eyes welled up with tears and she looked down again.

He winced, sinking lower into his seat, “Uh, they’ve been really helpful with our research in spirit, and helping me maintain a weapon form.” A sharp pang welled within his rib cage and he hung his skull down, “Hey…Tori? I need to-“

The room brightened as Toriel pulled back his hood and grabbed his mandible, making him look at her. She gasped in shock and reached out a shaky hand toward his right cheekbone, “What happened to your face?”

He glanced away, chuckling darkly, “Wow, that’s a little harsh.”

Her thumb traced along the lowest crack, pulling back when he flinched. She asked again, more firmly this time, “What happened?”

“I fell down.”

“You’re lying.”

“No I’m not. I told you I slipped a lot when I was wearing slippers.” He forced another laugh, “Maybe that’s where they get their name.”

“sans,” he stiffened at the tone in her voice, still avoiding her eyes. She kept hold of his mandible, firm but not painful, “Look me in the eyes and tell me that’s true.”

He scowled slightly and glared at the table. She knew he hated lying, especially to her. Slowly he turned his skull to face her, eye glowing with regret. “Promise you won’t get mad?”

Her eyebrows knit together, and she released her hold on him, “Usually that’s a bad sign when you say that to someone. It means you know what you have to tell me will upset me.”

He forced a smile, tears welling up in his left eye socket, voice growing hoarse, “Tori….”

Toriel’s expression softened and she leaned back in her chair, “I will try to remain calm.”

He tilted his skull down in shame, “Ok-“ A loud bang startled him and he glanced back toward the direction of the door, “-I don’t have a ton of time to explain everything, but,” He looked back at Toriel, “I…I brought…your human with me.”

Her hands flew to her mouth and she gasped, “M-my human? Really?” She stood, looking around him, “Where are they?”

Shakily, he slowly drew his hand away from his sternum revealing a small red heart glowing softly. A human’s soul. Toriel’s human. He looked down at his untouched slice of pie and held it out to her, “I didn’t mean for this to happen.” Tears dripped down his cheekbone at her cry of shock and pain.

“What did you do!?” She exclaimed, taking the soul from his hands and turning away. “You were supposed to protect them, sans!”

He let his arm drop, “I didn’t do it!” Gritting his teeth, he struck the table with his fist. He may as well have.  
She wept, hugging the soul to her chest, “I shouldn’t have let them go with you. I knew it was dangerous, but they were so determined to help.”

He stood up, looking up a the ceiling and growing antsy at the banging echoing down the corridor. “Toriel, I swear I never meant for this to happen.” Images of vines rising up and a demonic grin flashed in his mind, and he growled. “I can fix it, I swear I-“

She whirled around, tears streaming down her face and soaking her fur, “How can you fix it, sans? They’re dead!” She held out the soul to him, grief and sorrow reflected in her eyes, “How can you fix this?”

He opened his mouth to speak. He had to explain quickly. There was still time. There still had to be time. Toriel was a much better fighter than he was, and even though the human was gone… Surely there had to be a way to use their soul to resonate spirit. “Toriel, just listen. I have a plan-“

_You really are an idiot._ A voice echoed in his mind, and the ring in his eye spun. Laughter bounced around his skull, _You made this all too easy._

“sans?” Toriel’s voice sounded so far away, and the human’s soul was the only thing he could see clearly. “sans, how do we fix this?”

He stared at the soul, fear welling up within his own. _You know… Spirit isn’t the only thing amplified with a human’s soul._ Black corrupted spirit leaked out from the heart, twisting and curling around Toriel’s arms. She yelped in panic and stumbled back, still clutching the soul to her chest. _We wouldn’t have been able to reach the Ruins without your help, sans._

He blinked rapidly and focused on her face, “Toriel?” Her expression had darkened, arms falling to her sides. He reached out nervously to her, taking a half step forward, “T-Tori?” The soul pulsed in front of her, wisps of corruption pouring out and spreading across the floor and ceiling. His breathing became irregular, and he stayed where he stood. He refused to believe Toriel was gone too. He whispered gently, “Hey…Toriel?”

Her head wiped up, eyes black and teeth bared, “You murderer!”

“N-no I didn’t-“ He held up his hands, trying to placate her, “Please Toriel, you have to remain calm.”

She reached out to him as well and he smiled briefly. She has to be able to fight the effects, right? His smile faded as she clenched her fist and snarled at him, “Don’t you dare tell me to remain calm, sans!”

He stepped back, tripping on the chair, “Sorry, you’re right. That was rude of me.”

“Rude? Rude?!” Her eyes blazed with anger and she hissed, “My human is dead and you’re worried about being rude?!”

Her arm started to glow and he shook his skull rapidly, waving his arms. “No, that’s not what I meant. You know that’s not what I meant!”

“Shut up, sans!” she shouted, squeezing her eyes shut. The soul pulsed again, vanishing from sight and he tilted his skull to the side. She was shaking and breathing irregularly, but didn’t seem like she was going to attack. What kind of weapon was she anyway? Why couldn’t he remember? He opened his mouth to speak again, and her eyes focused on his as her arm morphed into a long barrel.

“Oh shit I forgot-“

“You traitor!” A jet of flame rocketed toward him, slamming him in the sternum and sending him flying backward through the window. Crashing glass and scraping bones echoed in the empty room, and he got up quickly, swatting at the flames that rose.

“Shit, shit.” He pulled off his jacket and shirt, stamping out the fire.

“sans!” Toriel shouted, drawing his attention up to the window. He cursed and picked up his jacket, sprinting down the corridor before she could finish what she wanted to say. His footsteps pounded against the ruined floor, the sound reverberating off the walls and back to him again and again. Tugging his jacket back on, he kept his eye forward and tried to ignore the whooshes of fire behind him. He searched frantically for a glitch in space, but still couldn’t find one.

“God dammit why can’t I teleport?!” He yelled, urging himself to run faster still. He ignored the Froggits and Whisum scattered throughout the corridors and looking at him with confusion. A whip shot out from the darkness and curled around his ankles, sending him falling to the ground. “Fuck!” He caught himself and turned, tugging at his legs. “Let me go!”

The Froggit growled, pulling him back and bracing its legs against the ground. He squeezed his eye socket shut, “Sorry!” and kicked it in the face, forcing it to release its hold. The Froggit yelped, but he didn’t look back to see if it was ok, already up on his feet and running.

He navigated through the puzzles easily enough, zigzagging the spikes through the false ones and glancing back. The faint orange glow of Toriel’s fire followed him, and he sped around another corner. He made it through another doorway when Toriel shouted again, “Where do you think you’re going, sans? You can’t escape.”

He panted, turning back to face her with rib cage heaving. She was right, he wouldn’t be able to escape. He looked from the door to the switches on the ground, and back to Toriel. At least he could buy himself some time. He stretched out his arm, morphing it into a scythe and cut through the switches to destroy the mechanism. The door slammed down to the ground and he sprinted away further.

The muffled sounds of Toriel traveled down the corridor, chasing him no matter how far he ran. He finally reached the end and rested his hands against the wall, rib cage heaving. Now what? He shook, a choked sob escaping him as he pressed his forehead against stone. “What do I do? Papyrus…Toriel…” Tears dripped to the floor, “Why…Why did things turn out this way?” The tips of his phalanges scraped against the wall, “What do I do?” He looked up at the light shining down, sighing in defeat. “There has to be something. Anything.” He stepped back and drew out his soul, holding it high above his head. His regret, desperation, and sorrow thrummed deep within him and a beacon of turquoise and golden light shined forth. Closing his eye socket, he spoke, projecting his hopes and fears with his soul. “Please! There has to be someone out there! Someone who remembers us. Someone who believes in us.” He clenched his fist at his side, “Please… help me.” He grit his teeth, “Help me save my friends…my brother…” He opened his eye socket and shouted, “I don’t care what it takes! I’ll even give you my soul so you can leave!” Black corrupted spirit curled and ran across the floor, reaching out to him. He hissed in pain as his soul began to turn black, and stumbled away to the furthest corner of the room, pressing his spine against the wall. He sank down to the floor, hugging his soul to his sternum and bringing his knees up to his chest. He pressed his forehead against his knees, mumbling quietly, “I just want my brother back… I don’t want forgiveness. Please, just help me get him back.”

**Author's Note:**

> If you have any questions about this feel free to ask! I have shared a lot of information on my Tumblr as well. I'm not sure if I'll write more or when I'll be able to since other stories need to be completed as well.
> 
> I am also open for commissions too, so if you'd like to commission me to write something email me at: skelegirl.fanfic@gmail.com


End file.
